1. Technical Field
The present invention relates to a recording unit having a damper member.
2. Related Art
As one type of recording unit that causes a liquid (an ink, for example) to adhere to a recording medium (paper, for example) for recording, an ink jet printer (simply referred to below as a printer) is known that ejects an ink from a recording section (a recording head, for example) to paper to record a prescribed image (including characters and figures). To record an image on paper, this type of printer takes out paper from a paper supply cassette (simply referred to below as a cassette), in which a plurality of sheets of paper are stacked, one at a time sequentially from the uppermost sheet. Accordingly, the printer includes an mounting section in which the cassette including a plurality of stacked sheets of paper is mounted so as to be removable by inserting and removing the cassette orthogonally to a direction in which the paper is stacked, and also has a paper feed roller that takes out paper one sheet at a time from the cassette mounted on the mounting section and sequentially feeds the paper to a recording section.
This type of printer has a separating slope at the inner back of the mounting section, in which the cassette is mounted, that is a section opposite to the front end of the cassette mounted in the mounting section in a direction in which the cassette is inserted, the separating slope being used to separate, one sheet at a time, the paper that is taken out of the cassette and is fed by the paper feed roller and to guide the separated paper toward the recording section. When mounting the cassette, the user may insert it into the mounting section at a faster speed. In this case, some stacked sheets may move from the cassette in the insertion direction due to an inertial force and may ride on the separation slope with a rising gradient. This prevents paper sheets from being separated one by one by the separating slope and causes multi-feeding, in which a plurality of stacked sheets are fed together, causing a risk of a paper jam or another problem.
To avoid the above problem, JP-A-2000-335769 describes a shutter member that is lowered from an upper evacuation position to a lower restricting position to restrict the movement of an end of paper, which is on the downstream side in the direction in which the paper is fed in the direction in which the cassette is inserted (the end of the paper in this direction will be referred to below as the front end of the paper). When the shutter member is raised from the lower restricting position, at which the shutter member is brought into contact with the front ends of sheets of paper, to the upper evacuation position, the lower end of the shutter member is rotated toward the upstream of the paper feed direction. This enables the front ends of the sheets of paper with which the shutter member is brought into contact to sequentially match the slop formed downstream in the paper feed direction as the paper is placed on the upper position in the stacking direction.
In JP-A-2000-335769, however, the shutter member is slid to the evacuation position while it is being rotated, so a space is necessary to dispose a rotating mechanism and a sliding mechanism, which are used to have the shutter member carry out the sliding and rotation. Another space is also necessary to accommodate the shutter member, rotating mechanism, and sliding mechanism at the evacuation position. These necessary spaces cause the size of the printer to increase.
A structure has been proposed in view of this situation, in which, for example, a restricting member is included, which has a restricting surface restricting the movement of paper toward the front in the cassette insertion direction, and rotates so as to fall down in the insertion direction. Specifically, the movement of the paper is restricted by the restricting surface to suppress its force, after which a rotational operation is performed after a prescribed delay in time to cause the restricting surface to fall down and evacuate from the separation slope, releasing the paper movement restriction. Therefore, the paper is separated one sheet at a time and guided toward the recording section, without riding on the separation slope. This eliminates the need for a large space in which to accommodate the shutter member, rotating mechanism, and sliding mechanism; only an additional space for a mechanism required for the rotational operation of the restricting member is needed, suppressing the printer from becoming large.
A damper member is used to cause the prescribed delay in time that lasts from when the paper is restricted until the restricting surface falls down in the rotational operation of the restricting member. Specifically, in the rotational operation of the restricting member, the prescribed delay in time is caused by the damper member in which a viscous material is applied between the sliding surfaces of a first member and a second member, which face each other during sliding, the first member and second member relatively moving (sliding) to cause the restricting member to rotate from the restricting position, at which the restricting member restricts the movement of the paper, to a releasing position, at which the restriction is released.
If the viscous material is a fluid such as grease or oil, however, the viscous material, which is applied between the abutting surfaces of the two members, is likely to adhere to areas other than the abutting surfaces of the two members by extending beyond the abutting surfaces and is thereby likely to be lost. This may change a damper force. Furthermore, the damper member may be dirtied by the viscous material that has adhered to the other areas and the printer may also be dirtied.